Energy delivery devices and methods

ABSTRACT

This relates to methods and devices for achieving contact between the wall of a cavity or passageway and a medical device when used in tortuous anatomy.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/860,216, filed Apr. 10, 2013, which is a continuation of U.S. patentapplication Ser. No. 13/087,161, filed Apr. 14, 2011 (now abandoned),which is a continuation of U.S. patent application Ser. No. 11/618,533,filed Dec. 29, 2006 (now U.S. Pat. No. 7,949,407), which is acontinuation-in-part of U.S. patent application Ser. No. 11/256,295,filed Oct. 21, 2005 (now U.S. Pat. No. 7,200,445) and U.S. patentapplication Ser. No. 11/420,442, filed May 25, 2006 (now U.S. Pat. No.7,853,331), which is a continuation of PCT Application No.PCT/US2005/040378, filed Nov. 7, 2005, which claims the benefit of U.S.Provisional Patent Application No. 60/625,256, filed Nov. 5, 2004, and60/650,368, filed Feb. 4, 2005, the full disclosures of which areincorporated herein by reference.

BACKGROUND OF THE INVENTION

Asthma is a disease in which (i) bronchoconstriction, (ii) excessivemucus production, and (iii) inflammation and swelling of airways occur,causing widespread but variable airflow obstruction thereby making itdifficult for the asthma sufferer to breathe. Asthma is a chronicdisorder, primarily characterized by persistent airway inflammation.However, asthma is further characterized by acute episodes of additionalairway narrowing via contraction of hyper-responsive airway smoothmuscle.

Asthma is managed pharmacologically by: (1) long term control throughuse of anti-inflammatories and long-acting bronchodilators and (2) shortterm management of acute exacerbations through use of short-actingbronchodilators. Both of these approaches require repeated and regularuse of the prescribed drugs. High doses of corticosteroidanti-inflammatory drugs can have serious side effects that requirecareful management. In addition, some patients are resistant to steroidtreatment. The difficulty involved in patient compliance withpharmacologic management and the difficulty of avoiding stimulus thattriggers asthma are common barriers to successful asthma management.

Current management techniques are neither completely successful nor freefrom side effects. Presently, a new treatment for asthma is showingpromise. This treatment comprises the application of energy to theairway smooth muscle tissue. Additional information about this treatmentmay be found in commonly assigned patents and applications in U.S. Pat.Nos. 6,411,852, 6,634,363 and U.S. published application nos.US-2005-0010270-A1 and US-2002-0091379-A1, the entirety of each of whichis incorporated by reference.

The application of energy to airway smooth muscle tissue, when performedvia insertion of a treatment device into the bronchial passageways,requires navigation through tortuous anatomy as well as the ability totreat a variety of sizes of bronchial passageways. As discussed in theabove referenced patents and applications, use of an RF energy deliverydevice is one means of treating smooth muscle tissue within thebronchial passageways.

FIG. 1A illustrates a bronchial tree 90. As noted herein, devicestreating areas of the lungs must have a construction that enablesnavigation through the tortuous passages. As shown, the variousbronchioles 92 decrease in size and have many branches 96 as they extendinto the right and left bronchi 94. Accordingly, an efficient treatmentrequires devices that are able to treat airways of varying sizes as wellas function properly when repeatedly deployed after navigating throughthe tortuous anatomy.

Tortuous anatomy also poses challenges when the treatment devicerequires mechanical actuation of the treatment portion (e.g., expansionof a treatment element at a remote site). In particular, attempting toactuate a member may be difficult in view of the fact that the forceapplied at the operator's hand-piece must translate to the distal end ofthe device. The strain on the operator is further intensified given thatthe operator must actuate the distal end of the device many times totreat various portions of the anatomy. When a typical device iscontorted after being advanced to a remote site in the lungs, theresistance within the device may be amplified given that internalcomponents are forced together.

It is also noted that the friction of polymers is different from that ofmetals. Most polymers are viscoelastic and deform to a greater degreeunder load than metals. Accordingly, when energy or force is applied tomove two polymers against each other, a significant part of frictionbetween the polymers is the energy loss through inelastic hysteresis. Inaddition, adhesion between polymers also plays a significant part in thefriction between such polymers.

In addition to basic considerations of navigation and site access, thereexists the matter of device orientation and tissue contact at thetreatment site. Many treatment devices make contact or are placed inclose proximity to the target tissue. Yet, variances in the constructionof the treatment device may hinder proper alignment or orientation ofthe device. For example, in the case of a device having a basket-typeenergy transfer element that is deployed intralumenally, the treatmentmay benefit from uniform contact of basket elements around the perimeterof the lumen. However, in this case, design or manufacturing variancesmay tend to produce a device where the angle between basket elements isnot uniform. This problem tends to be exacerbated after repeatedactuation of the device and/or navigating the device through tortuousanatomy when the imperfections of the device become worsened throughplastic deformation of the individual components. Experiencedemonstrates that once a member becomes predisposed to splaying (i.e.,not maintaining the desired angular separation from an adjacentelement), or inverting (i.e., buckling inward instead of deployingoutward), the problem is unlikely to resolve itself without requiringattention by the operator. As a result, the operator is forced to removethe device from the patient, make adjustments, then restart treatment.This interruption tends to increase the time of the treatment session.

As one example, commonly assigned U.S. Pat. No. 6,411,852, incorporatedby reference herein, describes a treatment for asthma using deviceshaving flexible electrode members that can be expanded to better fill aspace (e.g., the lumen of an airway.) However, the tortuous nature ofthe airways was found to cause significant bending and/or flexure of thedistal end of the device. As a result, the spacing of electrode memberstended not to be even. In some extreme cases, electrode elements couldtend to invert, where instead of expanding an electrode leg would invertbehind an opposing leg.

For many treatment devices, the distortion of the energy transferelements might cause variability in the treatment effect. For example,many RF devices heat tissue based on the tissue's resistive properties.Increasing or decreasing the surface contact between the electrode andtissue often increases or decreases the amount of current flowingthrough the tissue at the point of contact. This directly affects theextent to which the tissue is heated. Similar concerns may also arisewith resistive heating elements, devices used to cool the airway wall byremoving heat, or any energy transfer device. In any number of cases,variability of the energy transfer/tissue interface causes variabilityin treatment results. The consequential risks range from an ineffectivetreatment to the possibility of patient injury.

Furthermore, most medical practitioners recognize the importance ofestablishing acceptable contact between the transfer element and tissue.Therefore, distortion of the transfer element or elements increases theprocedure time when the practitioner spends an inordinate amount of timeadjusting a device to compensate for or avoid such distortion. Suchaction becomes increasingly problematic in those cases where properpatient management limits the time available for the procedure.

For example, if a patient requires an increasing amount of medication(e.g., sedatives or anesthesia) to remain under continued control forperformance of the procedure, then a medical practitioner may limit theprocedure time rather than risk overmedicating the patient. As a result,rather than treating the patient continuously to complete the procedure,the practitioner may plan to break the procedure in two or moresessions. Subsequently, increasing the number of sessions posesadditional consequences on the part of the patient in cost, the residualeffects of any medication, adverse effects of the non-therapeuticportion of the procedure, etc.

In view of the above, the present methods and devices described hereinprovide an improved means for treating tortuous anatomy such as thebronchial passages. It is noted that the improvements of the presentdevice may be beneficial for use in other parts of the anatomy as wellas the lungs.

SUMMARY OF THE INVENTION

The present invention includes devices configured to treat the airwaysor other anatomical structures, and may be especially useful in tortuousanatomy. The devices described herein are configured to treat withuniform or predictable contact (or near contact) between an activeelement and tissue. Typically, the invention allows this result withlittle or no effort by a physician. Accordingly, aspects of theinvention offer increased effectiveness and efficiency in carrying out amedical procedure. The increases in effectiveness and efficiency may beespecially apparent in using devices having relatively longer active endmembers.

In view of the above, a variation of the invention includes a catheterfor use with a power supply, the catheter comprising a flexible elongateshaft coupled to at least one energy transfer element that is adapted toapply energy to the body lumen. The shaft will have a flexibility toaccommodate navigation through tortuous anatomy. The energy transferelements are described below and include basket type design, or otherexpandable designs that permit reduction in size or profile to aid inadvancing the device to a particular treatment site and then may beexpanded to properly treat the target site. The basket type designs maybe combined with expandable balloon or other similar structures.

Variations of the device can include an elongate sheath having a nearend, a far end adapted for insertion into the body, and having aflexibility to accommodate navigation through tortuous anatomy, thesheath having a passageway extending therethrough, the passageway havinga lubricious layer extending from at least a portion of the near end tothe far end of the sheath. Where the shaft is slidably located withinthe passageway of the sheath.

Variations of devices described herein can include a connector forcoupling the energy transfer element to the power supply. The connectormay be any type of connector commonly used in such applications.Furthermore, the connector may include a cable that is hard-wired to thecatheter and connects to a remote power supply. Alternatively, theconnector may be an interface that connects to a cable from the powersupply.

As noted below, variations of the device allow for reduce frictionbetween the shaft and sheath to allow relatively low force advancementof a distal end of the shaft out of the far end of the sheath foradvancement the energy transfer element.

Additional variations of the invention include devices allowing forrepeatable deployment of the expandable energy transfer element whilemaintaining the orientation and/or profile of the components of theenergy transfer element. One such example includes an energy transferbasket comprising a plurality of legs, each leg having a distal end anda proximal end, each leg having a flexure length that is less than afull length of the leg. The legs are coupled to near and far alignmentcomponents. The near alignment component includes a plurality of nearseats extending along an axis of the alignment component. The nearalignment component can be secured to the elongate shaft of the device.The far alignment component may have a plurality of far seats extendingalong an axis of the alignment component, where the plurality of nearseats are in alignment with the plurality of far seats. In thesevariations of the device, each distal end of each leg is nested within afar seat of the far alignment component and each proximal end of eachleg is nested within a near seat of the near alignment component suchthat an angle between adjacent legs is determined by an angle betweenadjacent near seats and the flexure length of each length is determinedby the distance between near and far alignment components.

One or both of the components may include stops that control flexurelength of each leg. Such a design increases the likelihood that theflexure of each leg is unif rm.

An additional variation of the device includes a catheter for use intortuous anatomy to deliver energy from a power supply to a bodypassageway. Such a catheter includes an expandable energy transferelement having a reduced profile for advancement and an expanded profileto contact a surface of the body passageway and an elongate shaft havinga near end, a far end adapted for insertion into the body, theexpandable energy transfer element coupled to the far end of the shaft,the shaft having a length sufficient to access remote areas in theanatomy. The design of this shaft includes a column strength sufficientto advance the expandable energy transfer element within the anatomy,and a flexibility that permits self-centering of the energy transferelement when expanded to contact the surface of the body passageway.

BRIEF DESCRIPTION OF THE DRAWINGS

Each of the following figures diagrammatically illustrates aspects ofthe invention. Variation of the invention from the aspects shown in thefigures is contemplated.

FIG. 1 is an illustration of the airways within a human lung.

FIG. 2A is a schematic view of an exemplary system for delivering energyaccording to the present invention.

FIG. 2B is a side view of a device extending out of anendoscope/bronchoscope, where the device has an active distal end fortreating tissue using energy delivery.

FIGS. 3A-3G show various features of the device allowing for low forcedeployment of the energy element.

FIG. 3H illustrates a sheathless device having an oblong or oval shaftcross section.

FIG. 3I illustrates another variation of the device having a D-shapedcross section.

FIGS. 4A-4C illustrate various alignment components of the device.

FIGS. 4D-4E demonstrate the alignment components coupled to a leg of thedevice.

FIGS. 4F-4H illustrate an additional variation of an alignmentcomponent.

FIG. 4I illustrates yet another variation of an alignment component.

FIG. 4J illustrates an angle between basket electrode legs.

FIGS. 5A-5B is a variation of an energy transfer element according tothe present device.

FIGS. 5C-5D show variations in which the legs of the device are biasedto expand outward.

FIGS. 5E-5F illustrate another variation of the leg having a pre-shapedform.

FIGS. 5G-5I show further variations of the pre-bent legs.

FIGS. 5J-5L illustrate the pre-shaped legs in a collapsed and expandedconfiguration, wherein the proximal and distal alignment componentsextend within the expandable basket.

FIGS. 5M-5N illustrate the pre-shaped legs in an expanded configuration,wherein a basket support is disposed within the expandable basket.

FIGS. 6A-6C show various basket configurations for the device.

FIGS. 7A-7D illustrate various features of variations of legs for usewith the present devices.

FIGS. 8A-8D show various junctions for use with the present devices toimprove alignment when the device is advanced through tortuous anatomy.

FIGS. 9A-9J are addition variations of junctions.

FIGS. 10A-10D shows additional variations of junctions for use in thepresent devices.

FIG. 11 is a cross sectional view of an airway in a healthy lung.

FIG. 12 shows a section through a bronchiole having an airway diametersmaller than that shown in FIG. 11.

FIG. 13 illustrates the airway of FIG. 11 in which the smooth muscle 314has hypertrophied and increased in thickness causing reduction of theairway diameter.

FIG. 14 is a schematic side view of the lungs being treated with atreatment device 330 as described herein.

DETAILED DESCRIPTION

It is understood that the examples below discuss uses in the airways ofthe lungs. However, unless specifically noted, the invention is notlimited to use in the lung. Instead, the invention may haveapplicability in various parts of the body. Moreover, the invention maybe used in various procedures where the benefits of the device aredesired.

As described in U.S. Pat. No. 6,634,363, the entirety of which has beenincorporated by reference above, one way of improving airflow is todecrease the resistance to airflow within the lungs. There are severalapproaches to reducing this resistance, including but not limited toreducing the ability of the airway to contract, increasing the airwaydiameter, reducing the inflammation of airway tissues, and/or reducingthe amount of mucus plugging of the airway. Embodiments described hereininclude advancing a treatment device into the lung and treating the lungto at least reduce the ability of the lung to produce at least onesymptom of reversible obstructive pulmonary disease. The following is abrief discussion of some causes of increased resistance to airflowwithin the lungs and the treatment described herein. As such, thefollowing discussion is not intended to limit the aspects or objectiveof the method as the method may cause physiological changes notdescribed below but such changes still contributing to reducing oreliminating at least one of the symptoms of reversible obstructivepulmonary disease.

Reducing the Ability of the Airway to Contract

In embodiments, the inventive treatment reduces the ability of theairways to narrow or to reduce in diameter due to airway smooth musclecontraction. The treatment uses a modality of treatments including, butnot limited to the following: chemical, radio frequency, radioactivity,heat, ultrasound, radiant, laser, microwave, or mechanical energy (suchas in the form of cutting, punching, abrading, rubbing, or dilating).This treatment reduces the ability of the smooth muscle to contractthereby lessening the severity of an asthma attack. The reduction in theability of the smooth muscle to contract may be achieved by treating thesmooth muscle itself or by treating other tissues which in turninfluence smooth muscle contraction or the response of the airway to thesmooth muscle contraction. Treatment may also reduce airwayresponsiveness or the tendency of the airway to narrow or to constrictin response to a stimulus.

The amount of smooth muscle surrounding the airway can be reduced byexposing the smooth muscle to energy which either kills the muscle cellsor prevents these cells from replicating. The reduction in smooth musclereduces the ability of the smooth muscle to contract and to narrow theairway during a spasm. The reduction in smooth muscle and surroundingtissue has the added potential benefit of increasing the caliber ordiameter of the airways, this benefit reduces the resistance to airflowthrough the airways. In addition to the use of debulking smooth muscletissue to open up the airways, the device used in embodiments of thepresent invention may also eliminate smooth muscle altogether bydamaging or destroying the muscle. The elimination of the smooth muscleprevents the contraction or spasms of hyper-reactive airways of apatient having reversible obstructive pulmonary disease. By doing so,the elimination of the smooth muscle may reduce some symptoms ofreversible obstructive pulmonary disease.

The ability of the airway to contract can also be altered by treatmentof the smooth muscle in particular patterns. The smooth muscle isarranged around the airways in a generally helical pattern with pitchangles ranging from about −30 to about +30 degrees. Thus, the treatmentof the smooth muscle in appropriate patterns interrupts or cuts throughthe helical pattern of the smooth muscle at a proper pitch and preventsthe airway from constricting. This procedure of patterned treatmentapplication eliminates contraction of the airways without completelyeradicating smooth muscle and other airway tissue. A pattern fortreatment may be chosen from a variety of patterns includinglongitudinal or axial stripes, circumferential bands, helical stripes,and the like as well as spot patterns having rectangular, elliptical,circular or other shapes. The size, number, and spacing of the treatmentbands, stripes, or spots are chosen to provide a desired clinical effectof reduced airway responsiveness while limiting insult to the airway toa clinically acceptable level.

The patterned treatment of the tissues surrounding the airways withenergy provides various advantages. The careful selection of the portionof the airway to be treated allows desired results to be achieved whilereducing the total healing load. Patterned treatment can also achievedesired results with decreased morbidity, preservation of epithelium,and preservation of a continuous or near continuous ciliated innersurface of the airway for mucociliary clearance. The pattern oftreatment may also be chosen to achieve desired results while limitingtotal treatment area and/or the number of airways treated, therebyimproving speed and ease of treatment.

Application of energy to the tissue surrounding the airways may alsocause the DNA of the cells to become cross linked. The treated cellswith cross linked DNA are incapable of replicating. Accordingly, overtime, as the smooth muscle cells die, the total thickness of smoothmuscle decreases because of the inability of the cells to replicate. Theprogrammed cell death causing a reduction in the volume of tissue iscalled apoptosis. This treatment does not cause an immediate effect butcauses shrinking of the smooth muscle and opening of the airway overtime and substantially prevents re-growth. The application of energy tothe walls of the airway may also be used to cause a cross linking of theDNA of the mucus gland cells thereby preventing them from replicatingand reducing excess mucus plugging or production over time.

The ability of the airways to contract may also be reduced by alteringmechanical properties of the airway wall, such as by increasingstiffness of the wall or by increasing parenchymal tethering of theairway wall. Both of these methods increase the strength of the airwaywall and further oppose contraction and narrowing of the airway.

There are several ways to increase the stiffness of the airway wall. Oneway to increase stiffness is to induce fibrosis or a wound healingresponse by causing trauma to the airway wall. The trauma can be causedby delivery of therapeutic energy to the tissue in the airway wall, bymechanical insult to the tissue, or by chemically affecting the tissue.The energy is preferably delivered in such a way that it minimizes orlimits the intra-luminal thickening that may occur,

Another way to increase the effective stiffness of the airway wall is toalter the submucosal folding of the airway upon narrowing. The mucosallayer includes the epithelium, its basement membrane, and the laminapropria, a subepithelial collagen layer. The submucosal layer may alsoplay a role in airway folding. As an airway narrows, its perimeterremains relatively constant, with the mucosal layer folding upon itself.As the airway narrows further, the mucosal folds mechanically interferewith each other, effectively stiffening the airway. In asthmaticpatients, the number of folds is fewer and the size of the folds islarger, and thus, the airway is free to narrow with less mechanicalinterference of mucosal folds than in a healthy patient. Thus, asthmaticpatients have a decrease in airway stiffness and the airways have lessresistance to narrowing.

The mucosal folding in asthmatic patients can be improved by treatmentof the airway in a manner which encourages folding. Preferably, atreatment will increase the number of folds and/or decrease the size ofthe folds in the mucosal layer. For example, treatment of the airwaywall in a pattern such as longitudinal stripes can encourage greaternumber of smaller mucosal folds and increase airway stiffness.

The mucosal folding can also be increased by encouraging a greaternumber of smaller folds by reducing the thickness of the mucosa and/orsubmucosal layer. The decreased thickness of the mucosa or submucosa maybe achieved by application of energy which either reduces the number ofcells in the mucosa or submucosal layer or which prevents replication ofthe cells in the mucosa or submucosal layer, A thinner mucosa orsubmucosal layer will have an increased tendency to fold and increasedmechanical stiffening caused by the folds.

Another way to reduce the ability of the airways to contract is toimprove parenchymal tethering. The parenchyma surrounds airways andincludes the alveolus and tissue connected to and surrounding the outerportion of the airway wall, The parenchyma includes the alveolus andtissue connected to and surrounding the cartilage that supports thelarger airways. In a healthy patient, the parenchyma provides a tissuenetwork which connects to and helps to support the airway. Edema oraccumulation of fluid in lung tissue in patients with asthma or COPD isbelieved to decouple the airway from the parenchyma reducing therestraining force of the parenchyma which opposes airway constriction.Energy can be used to treat the parenchyma to reduce edema and/orimprove parenchymal tethering.

In addition, the applied energy may be used to improve connectionbetween the airway smooth muscle and submucosal layer to the surroundingcartilage, and to encourage wound healing, collagen deposition, and/orfibrosis in the tissue surrounding the airway to help support the airwayand prevent airway contraction.

Increasing the Airway Diameter

Hypertrophy of smooth muscle, chronic inflammation of airway tissues,and general thickening of all parts of the airway wall can reduce theairway diameter in patients with reversible obstructive pulmonary,disease. Increasing the overall airway diameter using a variety oftechniques can improve the passage of air through the airways.Application of energy to the airway smooth muscle of an asthmaticpatient can debulk or reduce the volume of smooth muscle. This reducedvolume of smooth muscle increases the airway diameter for improved airexchange.

Reducing inflammation and edema of the tissue surrounding the airway canalso increase the diameter of an airway. Inflammation and edema(accumulation of fluid) of the airway are chronic features of asthma.The inflammation and edema can be reduced by application of energy tostimulate wound healing and regenerate normal tissue. Healing of theepithelium or sections of the epithelium experiencing ongoing denudationand renewal allows regeneration of healthy epithelium with lessassociated airway inflammation. The less inflamed airway has anincreased airway diameter both at a resting state and in constriction.The wound healing can also deposit collagen which improves parenchymaltethering.

Inflammatory mediators released by tissue in the airway wall may serveas a stimulus for airway smooth muscle contraction. Therapy that reducesthe production and release of inflammatory mediator can reduce smoothmuscle contraction, inflammation of the airways, and edema. Examples ofinflammatory mediators are cytokines, chemokines, and histamine. Thetissues which produce and release inflammatory mediators include airwaysmooth muscle, epithelium, and mast cells. Treatment of these structureswith energy can reduce the ability of the airway structures to produceor release inflammatory mediators. The reduction in releasedinflammatory mediators will reduce chronic inflammation, therebyincreasing the airway inner diameter, and may also reducehyper-responsiveness of the airway smooth muscle.

A further process for increasing the airway diameter is by denervation.A resting tone of smooth muscle is nerve regulated by release ofcatecholamines. Thus, by damaging or eliminating nerve tissue in theairways the resting tone of the smooth muscle is reduced, and the airwaydiameter is increased. Resting tone may also be reduced by directlyaffecting the ability of smooth muscle tissue to contract.

FIGS. 11 and 12 illustrate cross sections of two different airways in ahealthy patient. The airway of FIG. 11 is a medium sized bronchus havingan airway diameter D1 of about 3 mm. FIG. 12 shows a section through abronchiole having an airway diameter D2 of about 1.5 mm. Each airwayincludes a folded inner surface or epithelium 310 surrounded by stroma312 and smooth muscle tissue 314. The larger airways including thebronchus shown in FIG. 11 also have mucous glands 316 and cartilage 318surrounding the smooth muscle tissue 314. Nerve fibers 320 and bloodvessels 322 also surround the airway.

FIG. 13 illustrates the bronchus of FIG. 11 in which the smooth muscle314 has hypertrophied and increased in thickness causing the airwaydiameter to be reduced from the diameter D1 to a diameter D3.

FIG. 14 is a schematic side view of the lungs being treated with atreatment device 330 as described in the references incorporated byreference herein, as set forth below. The treatment device 330 is anelongated member for treating tissue at a treatment site 334 within alung. The treatment device 330 may use a variety of processes to achievea desired response. The treatment device 330 may use a modality oftreatments as represented by the treatment source 332, including, butnot limited to the following: chemical, radio frequency, radioactivity,heat, ultrasound, radiant, laser, microwave, or mechanical energy (suchas in the form of cutting, punching, abrading, rubbing, or dilating).Although the invention discusses treatment of tissue at the surface itis also intended that the invention include treatment below anepithelial layer of the lung tissue.

As described in U.S. patent application Ser. No. 09/436,455 (now U.S.Pat. No. 7,425,212), the entirety of which has been incorporated byreference below, the airways which are treated with the device accordingto embodiments of the present invention are preferably 1 mm in diameteror greater, more preferably 3 mm in diameter. The devices are preferablyused to treat airways of the second to eighth generation, morepreferably airways of the second to sixth generation.

FIG. 2A shows a schematic diagram of one example of a system 10 fordelivering therapeutic energy to tissue of a patient for use with thedevice described herein. The illustrated variation shows, the system 10having a power supply (e.g., consisting of an energy generator 12, acontroller 14 coupled to the energy generator, a user interface surface16 in communication with the controller 14). It is noted that the devicemay be used with a variety of systems (having the same or differentcomponents). For example, although variations of the device shall bedescribed as RF energy delivery devices, variations of the device mayinclude resistive heating systems, infrared heating elements, microwaveenergy systems, focused ultrasound, cryo-ablation, or any other energydeliver system. It is noted that the devices described should havesufficient length to access the tissue targeted for treatment. Forexample, it is presently believed necessary to treat airways as small as3 mm in diameter to treat enough airways for the patient to benefit fromthe described treatment (however, it is noted that the invention is notlimited to any particular size of airways and airways smaller than 3 mmmay be treated). Accordingly, devices for treating the lungs must besufficiently long to reach deep enough into the lungs to treat theseairways. Accordingly, the length of the sheath/shaft of the device thatis designed for use in the lungs should preferably be between 1.5-3 ftlong in order to reach the targeted airways.

The particular system 10 depicted in FIG. 2A is one having a userinterface as well as safety algorithms that are useful for the asthmatreatment discussed above. Addition information on such a system may befound in U.S. Provisional application No. 60/674,106, filed Apr. 21,2005 entitled CONTROL METHODS AND DEVICES FOR ENERGY DELIVERY, theentirety of which is incorporated by reference herein.

Referring again to FIG. 2A, a variation of a device 100 described hereinincludes a flexible sheath 102, an elongate shaft 104 (in this example,the shaft extends out from the distal end of the sheath 102), and ahandle or other operator interface 106 (optional) secured to a proximalend of the sheath 102. The distal portion of the device 100 includes anenergy transfer element 108 (e.g., an electrode, a basket electrode, aresistive heating element, cryoprobe, etc.). Additionally, the deviceincludes a connector 110 common to such energy delivery devices. Theconnector 110 may be integral to the end of a cable 112 as shown, or theconnector 110 may be fitted to receive a separate cable 112. In anycase, the device is configured for attachment to the power supply viasome type connector 110. The elongate portions of the device 102 and 104may also be configured and sized to permit passage through the workinglumen of a commercially available bronchoscope or endoscope. Asdiscussed herein, the device is often used within an endoscope,bronchoscope or similar device. However, the device may also be advancedinto the body with or without a steerable catheter, in a minimallyinvasive procedure or in an open surgical procedure, and with or withoutthe guidance of various vision or imaging systems.

FIG. 2A also illustrates additional components used in variations of thesystem. Although the depicted systems are shown as RF type energydelivery systems, it is noted that the invention is not limited as such.Other energy delivery configurations contemplated may include or notrequire some of the elements described below. The power supply (usuallythe user interface portion 16) shall have connections 20, 28, 30 for thedevice 100, return electrode 24 (if the system 10 employs a monopolar RFconfiguration), and actuation pedal(s) 26 (optional). The power supplyand controller may also be configured to deliver RF energy to an energytransfer element configured for bipolar RF energy delivery. The userinterface 16 may also include visual prompts 32, 60, 68, 74 for userfeedback regarding setup or operation of the system. The user interface16 may also employ graphical representations of components of thesystem, audio tone generators, as well as other features to assist theuser with system use.

In many variations of the system, the controller 14 includes a processor22 that is generally configured to accept information from the systemand system components, and process the information according to variousalgorithms to produce control signals for controlling the energygenerator 12. The processor 22 may also accept information from thesystem 10 and system components, process the information according tovarious algorithms and produce information signals that may be directedto the visual indicators, digital display or audio tone generator of theuser interface in order to inform the user of the system status,component status, procedure status or any other useful information thatis being monitored by the system. The processor 22 of the controller 14may be digital IC processor, analog processor or any other suitablelogic or control system that carries out the control algorithms. U.S.Provisional application No. 60/674,106 filed Apr. 21, 2005 entitledCONTROL METHODS AND DEVICES FOR ENERGY DELIVERY the entirety of which isincorporated by reference herein.

As described in U.S. Patent Application Publication No. 2002/0091379,the entirety of which has been incorporated by reference above, thepower supply can include circuitry for monitoring parameters of energytransfer: (for example, voltage, current, power, impedance, as well astemperature from the temperature sensing element), and use thisinformation to control the amount of energy delivered. In the case ofdelivering RF energy, typical frequencies of the RF energy or RF powerwaveform are from 300 to 1750 kHz with 300 to 500 kHz or 450 to 475being preferred. The RF power-level generally ranges from about 0-30 Wbut depends upon a number of factors such as the size and number of theelectrodes. The controller may also be configured to independently andselectively apply energy to one or more of the basket leg electrodes.

A power supply may also include control modes for delivering energysafely and effectively. Energy may be delivered in open loop (power heldconstant) mode for a specific time duration. For example, a powersetting of 8 to 30 Watts for up to 10 seconds is suitable and a powersetting of 12 to 30 Watts for up to 5 seconds is preferred. For morepermanent restructuring of the airways, a power setting of 8 to 15 Wattsfor 5 to 10 seconds is suitable. For mere temporary relief orenlargement of the airway, a power setting of 10 to 25 Watts for up to 3seconds is suitable. With higher power settings, correspondingly lowertime durations are preferred to limit collateral thermal damage.

Energy may also be delivered in temperature control mode, with outputpower varied to maintain a certain temperature-for a specific timeduration. For example, energy may be delivered for up to 20 seconds at atemperature of 55 to 80 degrees C., and more preferably, energy isdelivered up to 10 seconds at a temperature in the range of 60 to 70degrees C. For more permanent restructuring of the airways, energy isdelivered for 5 to 10 seconds at a temperature in the range of 60 to 70degrees C. For mere temporary relief or enlargement of the airway,energy is delivered for up to 5 seconds at a temperature of 55 to 80degrees C. Additionally, the power supply may operate in impedancecontrol mode.

FIG. 2B illustrates one example of an energy transfer element 108. Inthis example the energy transfer element 108 is a “basket-type”configuration that requires actuation for expansion of the basket indiameter via a slide mechanism 114 on the handle 106. Such a feature isuseful when the device is operated intralumenally or in anatomy such asthe lungs due to the varying size of the bronchial passageways that mayrequire treatment. As illustrated, the basket contains a number of arms120 which carry electrodes (not shown). In this variation the arms 120are attached to the elongated shaft 104 at a proximal end while thedistal end of the arms 120 are affixed to a distal tip 122. To actuatethe basket 108 a wire or tether 124 is affixed to the distal tip 122 toenable compression of the arms 120 between the distal tip 122 andelongate sheath 104.

FIG. 2B also illustrates the device 100 as being advanced through aworking channel 33 of a bronchoscope 18. While a bronchoscope 18 mayassist in the procedure, the device 100 may be used through directinsertion or other insertion means as well.

As noted above, some variations of the devices described herein havesufficient lengths to reach remote parts of the body (e.g., bronchialpassageways around 3 mm in diameter). FIGS. 3A-3G illustrate variousconfigurations that reduce the force required to actuate the device'sbasket or other energy transfer element.

FIG. 3A illustrates a cross section taken from the sheath 102 andelongate shaft 104. As shown, the sheath 102 includes an outer layer 126and an inner lubricious layer 128. The outer layer 126 may be anycommonly known polymer such as Nylon, PTFE, etc. The lubricious layers128 discussed herein may comprise a lubricious polymer (for example,HDPE, hydrogel, polytetrafluoroethylene). Typically, lubricious layer128 will be selected for optimal pairing with the shaft 104. One meansto select a pairing of polymers is to maximize the difference in Gibbssurface energy between the two contact layers. Such polymers may also bechose to give the lubricious layer 128 a different modulus of elasticitythan the outer layer 126. For example, the modulus of the lubriciouslayer 128 may be higher or lower than that of the outer layer 126.

Alternatively, or in combination, the lubricious layers 128 may comprisea fluid or liquid (e.g., silicone, petroleum based oils, food basedoils, saline, etc.) that is either coated or sprayed on the interface ofthe shaft 104 and sheath 102. The coating may be applied at the time ofmanufacture or at time of use. Moreover, the lubricious layers 128 mayeven include polymers that are treated such that the surface propertiesof the polymer changes while the bulk properties of the polymer areunaffected (e.g., via a process of plasma surface modification onpolymer, fluoropolymer, and other materials). Another feature of thetreatment is to treat the surfaces of the devices with substances thatprovide antibacterial/antimicrobial properties.

In one variation of the invention, the shaft 104 and/or sheath 102 willbe selected from a material to provide sufficient column strength toadvance the expandable energy transfer element within the anatomy.Furthermore, the materials and or design of the shaft/sheath will permita flexibility that allows the energy transfer element to essentiallyself-align or self-center when expanded to contact the surface of thebody passageway. For example, when advanced through tortuous anatomy,the flexibility of this variation should be sufficient that when theenergy transfer element expands, the shaft and/or sheath deforms topermit self-centering of the energy transfer element. Examples of shaft104 or sheath 102 materials include nylon, PET, LLDPE, HDPE, Plexar PX,PTFE, teflon and/or any other polymer commonly used in medical devices.As described above, the inner or outer surfaces of the shaft 104 and/orsheath 102 may also comprise lubricant impregnations or coatings, suchas silicone fluid, carbon, PTFE, or any of the materials described withreference to lubricous layer 128. It is noted that the other materialselection and/or designs described herein shall aid in providing thisfeature of the invention.

FIG. 3A also depicts a variation of a shaft 104 for use in the presentdevice. In this variation the shaft 104 includes a corrugated surface130. It is envisioned that the corrugated surface 130 may includeribbed, textured, scalloped, striated, ribbed, undercut, polygonal, orany similar geometry resulting in a reduced area of surface contact withany adjoining surface(s). The corrugated surface 130 may extend over aportion or the entire length of the shaft 104. In addition, the shape ofthe corrugations may change at varying points along the shaft 104.

The shaft 104 may also include one or more lumens 132, 134. Typically,one lumen will suffice to provide power to the energy transfer elements(as discussed below). However, in the variation show, the shaft may alsobenefit from additional lumens (such as lumens 134) to supportadditional features of the device (e.g., temperature sensing elements,other sensor elements such as pressure or fluid sensors, utilizingdifferent lumens for different sensor leads, and utilizing separate orthe same lumen(s) for fluid delivery or suctioning, lumens for blowinggas (e.g., pressurized air, hot air) into the airway to move ordesiccate secretions (e.g., mucus) out of the way, etc.). In addition,the lumen(s) may be used to simultaneously or sequentially deliverfluids and/or suction fluid to assist in managing the moisture withinthe passageway. Such management may optimize the electrical coupling ofthe electrode to the tissue (by, for example, altering impedance).

Since the device is suited for use in tortuous anatomy, a variation ofthe shaft 104 may have lumens 134 that are symmetrically formed about anaxis of the shaft. As shown, the additional lumens 134 are symmetricabout the shaft 104. This construction provides the shaft 104 with across sectional symmetry that aid in preventing the shaft 104 from beingpredisposed to flex or bend in any one particular direction. Further,the shaft 104 may be designed to increase clearance between a centerwire 124 that runs through the shaft lumen 132 so as to minimizefriction and improve basket 108 deployment in tortuous anatomy. Stillfurther, the shaft 104 may be designed so as to efficiently transmittorque from the handle 106 to the basket array 108 in order to rotatethe basket array 108 within the airways so as to enhance devicepositioning. For example, this may be accomplished by incorporating abraided member (e.g., braided wire) into the shaft 104 extrusion or byjoining the shaft 104 coaxially with the braided member.

FIG. 3B illustrates another variation where the sheath 102 includes anouter layer 126 and a lubricious layer 128. However, in this variationthe lubricious layer 128 also includes a corrugated surface 136. It isnoted that any combination of the sheath 102 and shaft 104 may have acorrugated surface.

FIG. 3C illustrates yet another aspect of construction of a sheath 102for use with the present device. In this variation, the sheath 102includes a multi-layer construction having an outer layer 126, one ormore middle layers 138. The middle layers 138 may be selected to haveproperties that transition between the outer layer properties and thelubricious layer properties, and improve the bonding between inner andouter layer. Alternatively, the middle layer 138 may be selected to aidin the column strength of the device. An example of the middle layerincludes LLDPE, Plexar PX 306, 3060, and/or 3080.

FIG. 3D depicts a variation of a shaft 104 for use with the devicesdescribed herein where the shaft outer surface comprises a lubriciouslayer 140. As illustrated, the shaft outer surface may also optionallyhave a corrugated surface 130. FIGS. 3E-3G illustrate additionalvariations of corrugated surfaces. As shown in FIGS. 3E and 3F, eitheror both the sheath 102 and the shaft 104 may have corrugated surfacesthat are formed by interrupting the surface. Naturally, different shapesand configurations may be otherwise constructed. FIG. 3G illustrates avariation where the sheath 102 comprises protrusions or spacer 142 toseparate the surfaces of the sheath/shaft.

FIGS. 3H and 3I illustrate further variations of a shaft 104 which maybe incorporated within any of the devices described herein. FIG. 3Hillustrates a two lumen shaft 104 having an oblong or oval shaped crosssection. The first lumen 132 may be utilized to receive the conductivecenter wire 124 which electrically couples the legs 120 to the energygenerator 12. The second lumen 134 may be utilized to receivetemperature detecting leads 172 as described in more detail withreference to FIG. 7C. Further, a coil 135 or other reinforcing element(e.g., polymeric insert, braided member) may be utilized to preventkinking or collapse of the shaft 104, which is of particular benefitduring basket 108 deployment in tortuous anatomy. In this depiction, thecoiled wire 135 is disposed within lumen 132 of the shaft 104 andsurrounding the center wire 124. Referring now to FIG. 3I, a singlelumen shaft 104 having a D-shaped cross section is illustrated. Thesingle lumen 132 receives the center wire 124 as in FIG. 3H, but in thisembodiment the reinforcing coil 135 is disposed outside the shaft 104and further encompasses the temperature detecting leads 172. The coil135 may also reinforce a tubular sheath 102 which is disposed over thecoil 135 and extends along a length of the shaft 104. The embodiments ofFIGS. 3I and 3H also provide an exposed basket 108 configuration (e.g.,sheathless) which reduces friction and as such improves basket 108deployment mechanics.

These oblong, oval, or D-shaped shaft cross sections advantageouslyallow for a reduced profile while still axially centering the centerwire 124 with respect to the expandable basket 108. This reduced sizeprofile not only permits passage of the sheathless catheter of FIG. 3Hor sheathed catheter of FIG. 3I through the working channel lumen of anaccess device, such as a bronchoscope, but allows for fluid delivery orsuction through an opening created between the working channel lumen andan outer surface of the catheter. As already described above,alternatively or in the adjunct, additional lumens 134 within the deviceshaft 104 may be utilized for fluid delivery of cleaning fluids (e.g.,saline, bio-compatible fluids), drugs (e.g., lidocaine, tetracaine),cooling fluids (e.g., cooled saline, cooled sterile water, or otherfluids for cooling the airway wall), electrically conductive fluids(e.g., saline), thermally conductive fluids, or fluids to increase theviscosity of mucus so it can be more easily suctioned (e.g., saline), orfor suctioning of delivered fluids or excretions within the airway(e.g., mucus). Advantageously, suctioning or fluid delivery from or tothe airway may be accomplished while the asthma treatment device remainswithin the airways without requiring the device user to pull the deviceout of the airway, which in turn reduces procedure time and improvespatient manageability. For example, irrigation and/or suctioning may becarried out simultaneously or sequentially with energy delivery to theairway wall while the device is within the airway.

As described in U.S. Pat. No. 6,634,363, the entirety of which has beenincorporated by reference above, embodiments of the invention may alsoinclude the additional step of reducing or stabilizing the temperatureof lung tissue near to a treatment site. This may be accomplished forexample, by injecting a cold fluid into lung parenchyma or into theairway being treated, where the airway is proximal, distal, orcircumferentially adjacent to the treatment site. The fluid may besterile normal saline, or any other bio-compatible fluid. The fluid maybe injected into treatment regions within the lung while other regionsof the lung normally ventilated by gas. Or, the fluid may be oxygenatedto eliminate the need for alternate ventilation of the lung. Uponachieving the desired reduction or stabilization of temperature thefluid may be removed from the lungs. In the case where a gas is used toreduce temperature, the gas may be removed from the lung or allowed tobe naturally exhaled. One benefit of reducing or stabilizing thetemperature of the lung may be to prevent excessive destruction of thetissue, or to prevent destruction of certain types of tissue such as theepithelium, or to reduce the systemic healing load upon the patient'slung.

FIGS. 4A-4D illustrate yet another feature that may be incorporated withany of the subject devices. FIG. 4A illustrates an example of analignment component 150. In this variation, the alignment component 150includes a plurality of seats 152 that nest electrode arms (not shown).As discussed herein, the seats 152 allow for improved control of theangular spacing of the arms. Moreover, the seats 152 permits design of adevice in which the flexure length of each of the arms of a basket typedevice is uniform (even if the tolerance of each arm varies). Though thealignment component 150 is shown as having four seats 152, any number ofseats may be employed.

The alignment component 150 also includes a stop 154. The stop 154 actsas a reference guide for placement of the arms as discussed below. Inthis variation, the stop 154 is formed from a surface of an end portion158. This end portion 158 is typically used to secure the alignmentcomponent 150 to (or within) the sheath/shaft of the device. Thealignment component 150 may optionally include a through hole or lumen156.

FIG. 4B illustrates another variation of an alignment component 150.This variation is similar to the variation shown in FIG. 4A, with thedifference being the length of the end portion 158. The smaller endportion 158 may optionally be employed when the component 150 is used atthe distal end of the device. In such a case, the component 158 may notbe attached to the sheath or shaft. In addition, the end portion 158 mayoptionally be rounded, for example, to minimize tissue trauma that maybe caused by the end of the device.

The alignment components 150 of the present invention may be fabricatedfrom a variety of polymers (e.g., PEEK, ULTEM, PEI, nylon, PET and/orany other polymer commonly used in medical devices), either bymachining, molding, or by cutting an extruded profile to length. Onefeature of this design is electrical isolation between the legs, whichmay also be obtained using a variation of the invention that employs aceramic material for the alignment component. However, in one variationof the invention, an alignment component may be fabricated from aconductive material (e.g., stainless steel, polymer loaded withconductive material, or metallized ceramic) so that it provideselectrical conductivity between adjacent electrode legs and theconductive wire. In such a case, a power supply may be coupled to thealignment component, which then electrically couples all of the legsplaced in contact with that component. The legs may be attached to theconductive alignment component with conductive adhesive, or by solderingor welding the legs to the alignment component. This does not precludethe legs and alignment component form being formed from one piece ofmetal.

Devices of the present invention may have one or more alignmentcomponents. Typically the alignment components are of the same sizeand/or the angular spacing of the seats is the same. However, variationsmay require alignment components of different sizes and/or differentangular spacing. Another variation of the invention is to have the seatsat an angle relative to the axis of the device, so as to form ahelically shaped energy delivery element.

FIG. 4C illustrates another variation of an alignment component 150. Inthis variation, the alignment component 150 includes four seats 152.This variation includes an alignment stop 154 that protrudes from thesurface of the component 150. In addition, the end portion 158 of thealignment component 150 is also of a cross section that may improvestrength of the connection between the component and the sheath/shaft.In this case, the end portion 158 allows for crimping of thesheath/shaft. Optionally as shown, radial protrusions 178 at the rightof the end portion 158 may be included to allow heat bonding of thealignment component to the shaft. In this case, the shaft may be apolymer with a melting temperature lower than that of the alignmentcomponent. When constrained to be coaxial, heat, and if necessary axialpressure, may be applied to join the two components.

FIG. 4D illustrates the protrusion-type stop 154 that retains a notch162 of the electrode leg 160. This mode of securing the electrode leg160 provides a “redundant-type” joint. In one example, the leg 160 issecured to the alignment component 150 using a sleeve (not shown) placedover both the leg 160 and alignment component 150 with or without theuse of an adhesive within the sleeve. The notch 162 in the leg 160 isplaced around the protrusion-type-stop 154. As a result, the notch-stopinterface prevents the leg from being pulled from the device and isespecially useful to prevent the proximal or near ends of the legs fromseparating from the device. It is noted that this safety feature isespecially important when considering that if the proximal/near ends ofthe legs separate and hook on the anatomical passage, it may bedifficult or impossible to remove the device from the passage. Such afailure may require significant medical intervention.

FIG. 4E illustrates one example of a leg 160 affixed to near/proximaland far/distal alignment components 144, 146. As shown, the leg 160 mayhave an insulated portion 164 and an exposed portion 166 that formelectrodes. The near and far ends of the leg 160 are secured torespective alignment components 144, 146. In this example, sleeves 168and 170 cover the leg and alignment component. As noted above, one orboth of the alignment components may be electrically conductive toprovide power to the electrodes. Furthermore, adhesive (e.g.,cyanoacrylate (e.g., loctite), UV-cured acrylic, epoxy, and/or any suchadhesive) may also be used to secure the leg and/or sleeves to thecomponents.

Additionally, the alignment components may be designed such that thesleeves 168, 170 may be press or snap fit onto the alignment components,eliminating the need for adhesively bonding the sleeves to the alignmentcomponents. FIG. 4F illustrates a perspective view of an end portion ofan alignment component 150 having one or more slots 186 to create endportion segments 184. The slots 186 permit deflection of the end portionsegments 184 to allow sliding of a sleeve or hypotube (either a near orfar sleeve 168 or 170) over the end portion. FIG. 4G shows a crosssectional view of the component 150 of FIG. 4F. As shown, once advancedover the end portion segment 184, the sleeve or hypotube becomes securedto the component 150. To lock the sleeve in place, an insert or wiremember 124 (not shown) is placed in the through hole or lumen 156. Theinsert or wire member prevents inward deflection of the end portionsegments 184 thereby ensuring that the sleeve or hypotube remainssecured to the component 150.

Referring now to FIG. 41, another variation of the alignment component150 is shown. This proximal joint 150 is similar to that of FIG. 4C, buthas a reduced axial length by omission of the radial protrusions 178.This shortening improves joint flexibility in tortuous airways as a usercan translate the shaft 104 and basket assembly 108 with more easethrough the sheath 102 which in turn improves basket 108 deployment. Inthis embodiment, the end portion 158 may be directly coupled to theshaft 104 by utilizing heat shrink (e.g., PET) with a wicking adhesiveas described above. This coupling results in a lower proximal jointprofile so as to reduce the friction between the sheath 102 and shaft104 which in turn improves joint 150 flexibility and basket 108deployment. Further, in this embodiment, a PET shaft 104 may be utilizedto provide enhanced pushability of the shaft 104 so as to further aid inbasket 108 deployment and to reduce susceptibility to water absorptionso as to ensure greater consistency of deployed basket diameter(e.g., >10 mm).

As discussed herein, the seats 152 allow for improved control of theangular spacing of the legs 160. In particular, the seats 152 of theproximal and distal alignment components 144, 146 are aligned, whereinthe angle between adjacent legs 160 is determined by the angle betweenadjacent seat 152. The seats 152 preferably provide for symmetricaldeployment of the arms 160, wherein any angle between adjacent legsvaries less than 20 degrees. As shown in cross sectional view of FIG.4J, in the case of a four leg basket 108, the angle .alpha. betweenadjacent legs is in a range from about 70 degrees to about 110 degrees,preferably 90 degrees. Likewise, in the case of a six leg basket 108,the angle between adjacent legs is in a range from about 45 degrees toabout 75 degrees, preferably 60 degrees so that a variance is less than15 degrees. Further, in the case of a eight leg basket 108, the anglebetween adjacent legs is in a range from about 33 degrees to about 57degrees, preferably 45 degrees so that a variance is less than 12degrees or for a ten leg basket 108, the angle between adjacent legs isin a range from about 26 degrees to about 46 degrees, preferably 36degrees so that a variance is less than 10 degrees. Symmetricaldeployment ensures proper temperature distribution, which may beimportant for the treatment of asthma in the lung airways. It will beappreciated that the present invention is not limited to an even numberof basket legs 160. For example, five or seven basket legs 160 may beemployed as long as the spacing between each leg 160 is equivalent.

FIG. 5A shows a cross sectional view of two legs 160 attached toalignment components 144, 146. The sheath and shaft have been omittedfor clarity. The flexure length 164 of the leg 160 is defined as thelength between the alignment components 144, 146 over which the leg mayflex when the proximal and distal ends are moved closer to one another.As noted above, the alignment components permit the flexure length 164of the legs 160 to be uniform even if the leg lengths vary. The flexurelength 164 is essentially set by the longest leg, the shorter legs mayfloat between the stops 154 of the alignment components 144, 146. As anadditional measure to prevent the legs 160 from inverting, the lengthsof the sleeves 168 and 170 may be selected to be less than the length ofthe respective alignment components 144, 146 (as shown in the figure).The tendency of the leg to deflect outward can be improved by selectingthe sleeve length as such. When the legs 160 expand they are supportedby their respective seat on the interior side but unsupported on outerside. In yet another variation, the seats can slant to predispose thearms to deflect in a desired direction. For example, as shown in FIG.5C, the seats 152 can slant as shown to predispose the legs 160 tooutward deflection. Such a construction can be accomplished by machiningor by drafting a molded part in the direction of the catheter axis. Asshown in FIG. 5D, the leg can have a slight bend or shape thatpredisposes the legs to bow outward.

FIG. 5B illustrates the variation of FIG. 5A in an expanded state. Asshown, the device may have a wire 124 or other similar member thatpermits movement of the far alignment component 146 relative to the nearalignment component 144. As noted herein, the wire 124 may beelectrically conductive to provide power to electrodes on the device.FIG. 5B also illustrates a ball tip 148 at the end of the device. Theball tip 148 may serve as a means to secure the wire 124 as well asproviding an atraumatic tip for the device.

Variations of the wire 124 may include a braided or coiled wire. Thewire may be polymer coated or otherwise treated to electrically insulateor increase lubricity for easier movement within the device.

To expand the energy transfer element 108, the wire 124 may be affixedto a handle 106 and actuated with a slide mechanism 114 (as shown inFIG. 2A.) In an alternative design, the wire 124 may be affixed betweenthe handle 106 and the distal end of the energy transfer element 108. Insuch a case, the slide mechanism 114 may be affixed to the shaft 104.Movement of the slide mechanism 114 causes expansion of the element 108as the shaft 104 causes movement of the proximal end of the energytransfer element (being fixed to the shaft) relative to the distal endof the energy transfer element (being fixed to the wire 124). In anadditional variation, movement of the slide 114 may have two outcomes:1) advancing the energy transfer element out of the sheath; and 2)subsequently expanding the energy transfer element. Such constructionsare disclosed in U.S. patent application Ser. No. 09/436,455 filed Nov.8, 1999 the entirety of which is incorporated by reference herein. In astill further variation, movement of the slide 114 may cause the wire124 to be pulled proximally while the shaft 104 is pushed distally sothat energy transfer element remains stationary during deployment.

Referring now to FIGS. 5E-5N, the electrode legs 160 may be pre-shapedas already described herein. In particular, the electrodes 160 may bepre-shaped so as to control the direction in which the legs deflect uponbasket deployment 108 so as to prevent electrode inversion, providecontrolled buckling of the basket electrode 108, and improve tissuecontact. FIG. 5E illustrates a pre-bent leg 160 having four discretebends 161. As shown in FIG. 5F, when axial compressive loads 163 areapplied to the electrode 160 during deployment, the pre-shaped leg ispredisposed to buckle or deflect in a predictable, desired outwardsdirection 165 to make contact with the airway wall. Hence, thepre-shaped leg 160 provides for preferential buckling in the outwarddirection 165, which is of particular benefit in tortuous airways whereorthogonal or side loads commonly cause leg inversions. As illustratedin the example of FIG. 5F, an angle .beta. of the discrete pre-bends 161on the proximal and distal ends of the electrode 160 may be at an anglethat is in a range from about 10 degrees to about 20 degrees, preferably15 degrees.

It will be appreciated that several other pre-shaped variations may beemployed to induce buckling in the desired outward direction 165. Forexample, the pre-bent electrode may comprise a single bend 161 as shownin FIG. 5G, two bends 161 as shown in FIG. 5H, three bends 161 as shownin FIG. 5I, and the like. Further, the angle .beta. of the bend 161 orthe positioning of the bend 161 may vary depending on a variety offactors. Still further, the electrode 160 may be pre-shaped to form acontinuous curve, as illustrated in FIG. 2B, or a parabolic curve asillustrated below in FIG. 6A, or some other pre-shaped configuration inwhich a portion of the electrode 160 is out-of-plane from the axiallyactive compressive loads 163.

Referring now to FIGS. 5J-5L, cross sectional views of the pre-bent legs160 attached to proximal and distal alignment components 144, 146 areillustrated. The shaft 102 in this depiction has been omitted forclarity. In this particular embodiment, the alignment components extendwithin the expandable basket 108, as illustrated by reference numerals144 a, 146 a. As the basket is deployed, as shown in FIG. 5L, theproximal and distal extrusions or flanges 144 a, 146 a in the basket 108further prevent against electrode leg 160 inversions from the desiredoutward direction 165.

In addition or alternatively, inward leg buckling or inversions may alsobe prevented by disposing basket support(s) inside the expandable basket108. For example, as shown in the cross sectional view of FIGS. 5M and5N, a balloon member 171 may also be deployed inside the basket 108 andinflated to prevent inward deflection of the electrode legs 160.Further, the balloon member 171 may utilize its inflation lumen toreceive cooling fluids so as to cool the electrode 160 and airway wall.Still further, the balloon member 171 may also be utilized to deploy thebasket 108 in lieu of the pull wire 124.

FIG. 6A illustrates a variation of an energy transfer element 108 inwhich the legs 160 have a pre-determined shape. This shape may beselected as required for the particular application. As shown, thepredetermined shape provides a certain length of the electrode 166 thatmay be useful for treatment of a long section of tissue.

FIG. 6B illustrates another variation of the energy transfer element108. In this variation, the legs 160 extend out of openings 180 in thesheath 102 (in other variations, the legs may extend out of openings inthe shaft). Accordingly, the alignment components and other parts of thedevice would be located within the sheath 102.

FIG. 6C illustrates yet another variation of an energy transfer element108. In this variation, the basket is connected at a proximal end andopened at a distal end. The electrode legs 160 only have a singlealignment component 150. The conductive member (or wire) may be locatedwithin the shaft 104. In this variation, advancement of the energytransfer element 108 out of the sheath 102 causes expansion of theelement. The energy transfer elements may be predisposed or springloaded to bow outward when advanced from the sheath.

FIG. 7A illustrates an example of a leg 160 with an energy element 180coiled around the leg 160. In this example, the energy element 182 usesconductive heating and comprises a resistance heating element coiledaround the leg 160. FIG. 7B illustrates a variation of the inventionhaving an RF electrode attached to the basket leg 160. The RF electrodemay be attached to the basket leg 160 via the use of a fastener. Forexample, the electrode may be attached via the use of a heat shrinkfastener, (e.g., polymeric material such as PET or polyethylene tubing).Alternatively, as discussed above, the entire leg may be a conductivemedium where a non-conductive coating insulates the majority of the legleaving the electrode portion uninsulated. Further examples of energytransfer element configurations include paired bipolar electrodes, wherethe pairs are leg to leg or within each leg, and large matrices ofpaired electrodes affixed to a variety of expanding members (balloons,mechanisms, etc.)

FIG. 7C illustrates a variation of the invention having thermocoupleleads 172 attached to an electrode 166 or leg of the device. The leadsmay be soldered, welded, or otherwise attached. This variation of theinvention shows both leads 172 of the thermocouple 174 attached inelectrical communication to a leg 160 at separate joints (or the leadsmay be separated but the solder on each connection actually flowstogether). In this case, the temperature sensor is at the surface of theleg. This variation provides a safety measure in case either jointbecomes detached, the circuit will be open and the thermocouple 174stops reading temperature. Such a condition may be monitored via thepower supply and allow a safe shutdown of the system.

By spacing the leads of the thermocouple closely together to minimizetemperature gradients in the energy transfer element between thethermocouple leads, thermoelectric voltage generated within the energytransfer element does not compromise the accuracy of the measurement.The leads may be spaced as close together as possible while stillmaintaining a gap so as to form an intrinsic junction with the energytransfer element. In another variation of the device, the thermocoupleleads may be spaced anywhere along the tissue contacting region of theenergy transfer element. Alternatively, or in combination, the leads maybe spaced along the portion of an electrode that remains substantiallystraight. The intrinsic junction also provides a more accurate way ofmeasuring surface temperature of the energy transfer element, as itminimizes the conduction error associated with an extrinsic junctionadhered to the device.

The thermocouple leads may be attached to an interior of the leg orelectrode. Such a configuration protects the thermocouple as the deviceexpands against tissue and protects the tissue from potential trauma.The device may also include both of the thermocouple leads as having thesame joint.

The devices of the present invention may use a variety of temperaturesensing elements (a thermocouple being just one example, others include,infrared sensors, thermistors, resistance temperature detectors (RTDs),or any other component capable of detecting temperatures or changes intemperature). The temperature detecting elements may be placed on asingle leg, on multiple legs or on all of the legs.

The present invention may also incorporate a junction that adjusts formisalignment between the branching airways or other body passages. Thisjunction may be employed in addition to the other features describedherein. FIG. 8A illustrates a device 100 having such a junction 176allowing alignment of the device to closely match the alignment of theairway. It is noted that the present feature also benefits those casesin which the pathway and target site are offset as opposed to having anangular difference.

The junction 176 helps to eliminate the need for alignment of the axisof the active element 108 with the remainder of the device in order toprovide substantially even tissue contact. The junction may be a joint,a flexure or equivalent means. A non-exhaustive listing of examples isprovided below.

The legs 160 of the energy transfer element may have various shapes. Forexample, the shapes may be round, rounded or polygonal in cross section.Additionally, each leg may change cross section along its axis,providing for, for example, electrodes that are smaller or larger incross section that the distal and proximal portions of each leg. Thiswould provide a variety of energy delivery characteristics and bendingprofiles, allowing the design to be improved such that longer or widerelectrode configurations can be employed. For example, as shown in FIG.7D, if the cross-sectional thickness of the electrode portion 166 of theleg 160 is greater than the cross-sectional thickness of the distal andproximal portions of the leg, the leg would be predisposed to bowoutward in the distal and proximal sections, while remaining flatter inthe electrode area of the leg, potentially providing improved tissuecontact.

As for the action the junction enables, it allows the distal end of thedevice to self-align with the cavity or passageway to be treated,irrespective of the alignment of the access passageway. FIG. 8Aillustrates an example of where the access passageway and passageway tobe treated are misaligned by an angle .alpha. In the example shown inFIG. 8B, the misalignment angle .alpha. is greater than the angleillustrated in FIG. 8A. Yet, the energy transfer element 108 of thetreatment device 100 remains substantially aligned with the target area.

FIGS. 8C and 8D illustrate an additional variation of the junction 176.In this variation the junction 176 may be reinforced with a reinforcingmember 230. The reinforcing member may have some degree of flexibilityto navigate the tortuous anatomy, but the flexibility will be less thanthe junction 176. As shown in FIG. 8C, the reinforcing member 230maintains the device shaft 104 in an aligned position, preferably forinsertion, removal, and or navigation of the device. When desired, thereinforcing member 230 may be removed from the junction 176 asillustrated in FIG. 8D. Accordingly, upon removal, the device is free toflex or orientate as desired. Furthermore, the reinforcing member may bereinserted within the junction 176 when repositioning or removing thedevice from the target site. In additional variations, it iscontemplated that the reinforcing member may be placed external to thedevice/junction.

FIGS. 9A-9I illustrate additional junctions for use in the devicesdescribed herein. As for these examples, FIG. 9A illustrates a junction176 in the form of a plurality of turns or coils 200 of a spring. Thecoil offers a flexure with 3-dimensional freedom allowing realignment ofthe active end of the subject device in any direction. Of course, asimple hinge or universal joint may also be employed.

The length of the junction (whether a spring junction or some otherstructure) may vary. Its length may depend on the overall systemdiameter. It may also depend on the degree of compliance desired. Forexample, with a longer effective junction length (made by extending thecoil with additional turns), the junction becomes less rigid or more“floppy”.

In any case, it may be desired that the junction has substantially thesame diameter of the device structure adjacent the junction. In thisway, a more atraumatic system can be provided. In this respect, it mayalso be desired to encapsulate the junction with a sleeve or covering ifthey include open or openable structures. Junction 176 shown in FIGS. 8Aand 8B is illustrated as being covered. A covering can help avoidcontaminating the joint with body fluid or debris which could compromisejunction function.

Some of the junctions are inherently protected. Junction 176 shown inFIG. 9B comprises a polymer plug 220 or a section of polymer having adifferent flexibility or durometer than adjacent sections. When aseparate piece of polymer is to be employed, it can be chemically,adhesively, or heat welded to adjacent structure; when the junction isformed integrally, this may be accomplished by selective vulcanizing, orreinforcement (even with a braid or by other means of forming acomposite structure). Generally, it is noted that any connection ofpieces or construction provided may be produced by methods known bythose with skill in the art.

As for junction 176 shown in FIG. 9C, it is formed by removing sectionsof material from the body of the device. Openings 218 formed at thejunction may be left empty, covered or filled with a more compliantmaterial. FIG. 9D also shows a junction 176 in which openings areprovided to provide increased flexibility. Here, openings 218 are offsetfrom each other to form a sort of flexible universal joint. In eitherjunction variation shown in FIG. 9C or 9D, the size, number shape, etc.of the opening may vary or be tuned as desired.

FIG. 9E shows a junction 176 in the form of a bellows comprisingplurality of pleats 216. Here too, the number of pleats, etc. may bevaried to achieve desirable performance.

Junction 176 in FIG. 9F shows a true “joint” configuration. In thiscase, it is a universal joint provided by ball 204 and socket 206. Theseelements may be held together by a tie wire 208, possibly with caps 210.Other configurations are possible as well.

FIG. 9G illustrates a junction 176 in the form of a reduced diametersection 202. This variation offers greater flexibility by virtue of itsdecreased moment of inertia at the junction. While section 202 isintegrally formed, the related junction 176 in FIG. 9H is formed from ahypotube or wire 212 having an exposed junction section 214 on the shaft104. Variations of the invention will permit a junction having a reducedbending moment of inertia section as compared to the remainder of thedevice and/or shaft of the device. Reducing the bending moment ofinertia may be accomplished in any number of ways. For example, therecould be an area of reduced diameter, a section of material having alower modulus, a section having a different shape, a flexible jointstructure, etc. It should be noted that there are many additional waysto reduce the bending moment that will be readily apparent to thoseskilled in the art viewing the invention disclosed herein.

Yet another junction example is provided in FIG. 91. Here junction 176comprises a plurality of wires 222, 224, 226. In one variation, thewires simply offer increased flexibility of the junction. In anothervariation, the wires serve as an “active” or “dynamic” junction. Thewires may be adjusted relative to one another to physically steer thedistal end of the device. This junction may be manipulated manually withan appropriate user interface—especially one, like a joy-stick, thatallows for full 3-dimensional or rotational freedom—or it may becontrolled by automation using appropriate hardware and softwarecontrols. Of course, other “dynamic” junctions are possible as well.

FIG. 9J shows another joint configuration 176 employing an externalsleeve 262 between sections of the shaft 104. A moveable wire 124 toactuate a distal basket or the like is also shown. The space between thewire and sleeve may be left open as shown, or filled in with a flexiblepolymer 264, such as low durometer urethane, a visco-elastic material,etc. Though not necessary, providing an internal member may improvesystem pushability. The sleeve itself will typically be a polymericsleeve. It may be heat-shrink material such as PET tubing; it may beintegrally formed with either catheter body portion and press fit orslip fit and glued over other etc.

Another variation of the junctions includes junctions variations wherethe shaft 104 is “floppy” (i.e., without sufficient column strength forthe device to be pushable for navigation). In FIG. 10A, a tether 232connects energy transfer element 108 to the shaft 104 of the device 100.The tether may simply comprise a flexible wire or cable, it may comprisea plurality of links, etc. The tether variation of the invention alsoaccommodates relative motion between the device and the body (e.g.,tidal motion of breathing, other muscle contractions, etc.) The tetherpermits the device to move relative to its intended treatment locationunless the user desires and uses the tether or the sheath to pull thedevice back or drive it forward. The tether may have an alignmentcomponent (not illustrated) at the near end of the energy transferelement 108.

To navigate such a device to a treatment site, the energy transferelement 108 and tether 232 may be next to or within the sheath 102. Inthis manner, the column strength provided by the sheath allows foradvancement of the active member within the subject anatomy.

The same action is required to navigate the device shown in FIG. 10B.What differs in this variation of the invention, however, is that the“tether” is actually a continuation of a highly flexible shaft 104. Inthis Case, the shaft 104 of the device is shown with a thicker orreinforced wall. In such a device, the shaft carries the compressiveloads on the device back to its distal end.

Like the device in FIG. 10B, the devices in FIGS. 10C and 10D havehighly flexible shafts 104. However, instead of a stiffening externalsheath, the device may employ a stiffening obturator 230 within a lumenof the shaft 104. As shown in FIG. 10C, when the obturator 230 fills thelumen, the device is relatively straight or stiff. When the shaft iswithdrawn as shown in FIG. 10D, the distal end of the device is “floppy”or easily conformable to the subject anatomy. With the shaft advancedsubstantially to the end of the device, it offers ease of navigation;when withdrawn, it offers a compliant section according to an aspect ofthe present invention.

As for other details of the present invention, materials andmanufacturing techniques may be employed as within the level of thosewith skill in the relevant art. The same may hold true with respect tomethod-based aspects of the invention in terms of additional acts acommonly or logically employed. In addition, though the invention hasbeen described in reference to several examples, optionallyincorporating various features, the invention is not to be limited tothat which is described or indicated as contemplated with respect toeach variation of the invention.

Various changes may be made to the invention described and equivalents(whether recited herein or not included for the sake of some brevity)may be substituted without departing from the true spirit and scope ofthe invention. Also, any optional feature of the inventive variationsmay be set forth and claimed independently, or in combination with anyone or more of the features described herein. Accordingly, the inventioncontemplates combinations of various aspects of the embodiments or ofthe embodiments themselves, where possible. Reference to a singularitem, includes the possibility that there are plural of the same itemspresent. More specifically, as used herein and in the appended claims,the singular forms “a,” “and,” “said,” and “the” include pluralreferents unless the context clearly dictates otherwise.

1-25. (canceled)
 26. A method for treating a subject, the methodcomprising: damaging nerve tissue of a nerve trunk extending along anairway of a bronchial tree to attenuate nervous system signalstransmitted to a portion of the bronchial tree, wherein damaging thenerve tissue comprises increasing a temperature of the nerve tissue to afirst temperature while a portion of a wall of the airway is at a secondtemperature that is less than the first temperature, the portion of thewall is positioned radially inward from the nerve tissue at the firsttemperature.
 27. The method of claim 26, wherein damaging the nervetissue comprises irreversibly damaging the nerve tissue to at leastpartially block a transmission of nervous system signals and to cause apermanent decrease in smooth muscle tone of the portion of the bronchialtree.
 28. The method of claim 26, wherein damaging the nerve tissuecomprises: delivering energy to the nerve tissue; and destroying asection of the nerve tissue using the delivered energy such that thedestroyed section impedes transmission of nervous system signalstraveling along the nerve tissue.
 29. The method of claim 26, whereinthe nerve tissue is positioned along an airway 1 mm in diameter orgreater of the bronchial tree so as to attenuate the nervous systemsignals to a substantial portion of the bronchial tree distal to theairway.
 30. The method of claim 26, wherein the nerve tissue isgenerally positioned along an airway 1 mm in diameter or greater. 31.The method of claim 26, wherein damaging the nerve tissue includesablating nerve tissue along an airway 1 mm in diameter or greater. 32.The method of claim 26, further comprising cooling the airway wall whilethe nerve tissue is damaged.
 33. The method of claim 32, wherein coolingcomprises circulating a cooling fluid through a cooling elementpositioned in the airway.
 34. The method of claim 33, wherein the nervetissue is damaged using an energy delivery element positioned on oradjacent to the cooling element.
 35. The method of claim 32, whereincooling comprises delivering a cooling fluid into a cooling elementpositioned in the airway.
 36. The method of claim 35, wherein the nervetissue is damaged using an energy delivery element positioned on oradjacent to the cooling element.